Stamp-mill.



F. BASSETT.

STAMP NULL,

APPLICATION FILED MAY I8, 1915- um M M a ,d

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1 Jj J PLANOURAPH WASHINGTONAI. l

F. BASSETT.

STAMP MILL.

APPLICATION FILED MAY1B.1915.

2 SHEETS- SHEET 2.

Patented May 16, 1916.

TME coLUMlA VLANOGRAPH co., WASHINGTON. u. c,

FREDERICK BASSETT, 0F PHILIPSBURG, MONTANA.

STAMP-MILL.

Specification of Letters Patent.

Patented May 16, 1916.

Application filed May 18, 1915. Serial No. 28,872.

To all whom t 71mg/ concern:

Be it known that I, Fnnonnicn BAssE'rT, citizen of the United States, residing at Ihilipsburg, in the county of Granite and State of Montana, have invented certain new and useful Improvements in Stamp- Mills, of which the following is a specification.

This invention relates to apparatus employed for crushing gold and other ores or hard material that is to be crushed or pulverized, and more particularly to that class of apparatus which operates with a percussive action.

The invention has for its object to provide an apparatus of the kind stated which is vvery simple in construction, and highly efficient in operation, a vertically reciprocating and rotary stamp being provided which operates in conjunction with a mortar to crush and also to grind the ore or other material, the mortar being constructed to impart the reciprocatory movement to the stamp.

In order that the invention may be better understood, reference is had to the accompanying drawings in which- Figure 1 is an elevation of the apparatus. Fig. 2 is a vertical section thereof; Fig. 3 is a plan view; and Fig. 4 is a side elevation of the apparatus showing the feed mechanism.

Referring specifically to the drawing 5 denotes the mortar of the mill above which operates a stamp 6 which is slidably mounted on a vertical shaft 7 and also has a rotary movement. The shaft is stepped at the bottom in a suitable bearing 8 and passes through the center of the mortar above which it extends a suitable distance to accommodate the stamp. In order that the stamp may rotate with the shaft and also be free to slide up and down thereon, the shaft has long feathers 9 and the mortar has keyways 10 in which the feathers seat. On the top of the mortar are rigidly mounted shoes 11 having top inclines 12. The shoes are so positioned on the mortar that they form a series of inclines terminating in abrupt drops from the highest point of one incline to the bottom of the neXt incline. On the bottom of the stamp are mounted shoes 13 having bottom inclines 14, these shoes being arranged in the same manner as the shoes 11 and located opposite the same. The shoes 13 also correspond in number to the shoes 11 and their inclines have the same angle. It will therefore be evident that when the stamp is down as far as it can go, the inclines of the respective sets of shoes will be opposite each other, and when the stamp is rotated it will slide upward on the shaft 7, the inclines 12 of the shoes 11 acting as cams on the inclines l1 of the shoes 13 to lift the stamp, the mortar', of course, remaining stationary. lVhen the ends of the inclines 14 reach the highest points of the inclines 12, the shoes pass over the abrupt upper ends of the inclines 12, whereupon the stamp drops down, and the inclines 12 and 14 again come opposite each other, whereupon the stamp is again lifted. The material to be operated on is in the pockets formed by the inclines 12 and it is pounded by the shoes 13 as they descend and also ground by the inclines 14 by the movement thereof up the inclines12.

At the center of the mortar 5 is an upstanding hub 15 on which the stamp 6 turns and is guided, the stamp having the lower portion of its shaft opening enlarged sufficiently to receive the hub.

The shoes 11 are bolted to the top of the mortar 5 so that they may be removed and renewed when worn, and for the same reason the shoes 13 are removably fastened to the stamp 6.

The shaft 7 :is driven from any suitable source of power, a drive gear 16 being fast on the shaft beneath the mortar 5, 0r on the upper end of the shaft.

The mortar 5 is in the center of a trough 17 containing an annular screen 18 which encircles the impacting and grinding surfaces. The ground pulp splashes out through the screen into the trough on the outside thereof, and is discharged from the trough through an outlet 19. The material to be crushed and ground is fed in between the impacting and grinding surfaces.

In order to prevent wear of the keyways 10 they are lined with brasses 24. The stamp 6 will be of suiicient weight to Obtain the necessary crushing effect.

The following mechanism is provided for controlling the feed of material: Alongside the mill is mounted a hopper 25 beneath the bottom or discharge end of which is located a trough 26 which is inclined and has its lower end located over the screen 18 to discharge into the space between said screen and the irnpacting and grinding surfaces of the mill.

The trough is loosely hung from the hopper 25 by pivot links 27 in order that it may be given a reciprocatory, shaking motion. This motion is imparted t0 the trough by the stamp G through an angle lever Q8 pivoted at the angle to the side of the hopper as indicated at 29 and having one end connected by a link 30 to the rear end of the trough. The other end of the lever is in the path of an outstanding flange Q0 on the upper end of the stamp 6. At the end of the downward movement of the stamp 6 the flange Q0 strikes the lever 28 and through the lilik connection 30 of said lever with the trough Q6, the latter is carried rearward, and when the stamp 6 aseends and the flange Q0 leaves the lever, the trough swings forward, this forward movement being accelerated by a spring 31 abutting against its rear end. This backward and forward shuffling motion of the trough spills the material into the space between the screen 18 and the ilnpacting and grinding surfaces, and in order to force the material t0 said surfaces there is mounted in the space a scraper working on the bottom of the screen and at such a height as to carry the material upward to come between the inclined surfaces l2 and 14. The scraper is carried by the stamp G and rotates therewith, the connection being made by a resilient rod 33 fastened to the side of the stamp, said rod yieldingly pressing with the scraper to the bottom of the screen. The length of the rod is such that the scraper remains in contact with the bottom of the screen as the stamp rises. One scraper is shown, but it will be evident that any number may be employed.

The hopper 25 carries a screw 34 which is in the path of the lever Q8 to intercept the same and thus limit the swing of the trough 26, thereby regulating and controlling the feed from the hopper. The feed is further controlled by the screw, as by screwing the same downward the lever is pressed away from the flange 20, and the lower it is pressed, the less material will be shaken from the trough as the latter will not have such a violent shake.

Copies of this patent may be obtained for ve cents each, by addressing the I claim 1. A stamp mill comprising a stationary mortar having a crushing and grinding surface composed of a series of inclines terminating in abrupt drops, a rotatable vertical shaft above the mortar, a stamp rotatable with and slidable up and down on the shaft, the bottom of the stamp having crushing and grinding surfaces matching the crushing and grinding surface of the mortar, and a stationary upstanding hub at the center of the mortar, on which the stamp loosely seats.

2. A stamp mill comprising a stationary mortar having a crushing and grinding surface composed of a series of inclines terminating in abrupt drops, a rotatable vertical shaft above the mortar, a stamp rotatable with and slidable up and down on the shaft, the bottom of the stamp having crushing and grinding surfaces matching the crushing and grinding surface of the mortar, a screen surrounding said grinding surfaces, a trough in which the screen is located and into which the material is discharged from the screen, and a scraper located inside the screen, said scraper being connected to the stamp to travel therewith.

3. A stamp mill comprising a stationary mortar having a crushing and grinding surface composed of a series of inclines terminating in abrupt drops, a rotatable vertical shaft above the mortar, a stamp rotatable with and slidable up and down on the shaft, the bottom of the stamp having crushing and grinding surfaces matching the crushing and grinding surface of the mortar, a screen surrounding said grinding surfaces, a trough in which the screen is located and into which the material is discharged from the screen, and a scraper located inside the screen, said scraper being connected to the stamp t0 travel therewith, the connection being a resilient one.

In testimony whereof I afliX my signature in presence of two witnesses.

FREDERICK BASSETT.

Witnesses:

B. A. DAVIDSON, DAVID M. DURFEE.

Commissioner of ratexts.

Washington, D. C. 

